When you like something that suits your taste and budget, you want it immediately or without much delay. Be that your dream car, pizza, or eyeglasses, you want it now. But the fact remains that anything made hurriedly (even a soup) would not be as desired, ending in an unpleasant experience.
We are not talking about cars or food here, but eyeglasses. Although modern technology has helped in speeding up the production of eyewear, there is a process that it undergoes. You can purchase some frames and lenses over the counter but some require to be made as per your order.
If you have a doctor’s prescription, the refractive index of the lens and coatings like blue blocking, photochromic, mirrored, etc., would affect the delivery time. Here we give you some interesting insights into the process of making eyeglasses and how long it takes to make one. Although it doesn’t take too long to get your choice of eyeglasses, this article will help you understand it is worth the wait.
How Are Eyeglasses Made?
Getting a blank lens is an initial step in creating a power lens. The "plus" convex side of the lens is already cut and polished. A coating is applied on the plus side and then a block is attached at the appropriate axis and "prism".
The lens is then placed inside a device that grinds the lens's "minus" concave side and also adjusts its thickness. We can shape this side into a "sphere," where the ground radius is constant regardless of the lens's angle, or into a "cylinder," where two separate radii are generated at right angles to one another.
After that, we put the ground lens inside a "fining" mechanism that significantly increases its precision while employing a tool that replicates the ground surface radius. By pouring a specific fining fluid onto the tool, the lens surface is gradually ground to a slightly hazy state.
We mark the shape of the lens to indicate where it would be placed on a set of frames and on the axis of the lens. After being ground, we fit the lens to a machine that follows a template that matches the frame to which it will be fitted.
Next, the lens is air- or immersion-hardened, tested again, and if necessary, a color tint is applied. After being tested and checked by a qualified technician, the lens is then put back into the frame and shipped to the doctor.
What is The Average Time to Make Glasses?
It is indeed a lengthy process, but modern manufacturing units have simplified it. Without considering hardening or fitting into the frame, manufacturing a glass blank into a finished lens takes roughly 45 minutes of work time.
You may wonder why it takes longer to get prescription glasses than sunglasses. Although both are different categories of eyewear and both need sophisticated features added to the lenses. So, why it takes longer than the other?
Let’s compare this with a drive-in fast-food outlet. You drive to the order-taking window and place your order – burgers, tacos, sandwiches, salads, etc. By the time you pay and move on to the takeaway counter, the food is ready. Amazing, isn’t it?!
Try this at a downtown restaurant; your order for a specific dish might take at least 20 minutes or more to serve on your table. Why? Are the staffs at the restaurant slow or sleeping? Nope. The cooking time depends on how it is prepared. A fast-food outlet already has all the ingredients of a dish already prepared, they just need to be assembled and packed. But a restaurant is actually cooking it only after you place the order.
Getting your sunglasses or prescription glasses more or less works on similar lines.
While sunglasses lenses are mass manufactured with variations of available features, and already come affixed on the frames; it just needs to be packed. Prescription glasses are made-to-order products.
Let’s understand the process of prescription glasses.
You are purchasing an exact frame, a lens customized for that frame, and a lens made of an appropriate substance with a refractive index to suit your vision. Furthermore, you may choose from a variety of coatings, including anti-reflection, transition, tinting, and mirror coatings.
This you surely wouldn’t get immediately off the shelf. Remember, your order was placed at the restaurant?
It is necessary to grind and polish the lenses, add coatings, and then fit the lenses into your frames. Sometimes the complete process is done elsewhere and needs to be delivered at the optical store. So, handling, packing, and logistics will take their own time.
If a team was committed to a small clientele, it could complete them in a single day. However, you could expect to pay five times more!
If this sounds too much of a botheration to get a pair of glasses, it may amaze you that it was much more difficult two decades ago. But the good news is that optometry technology has advanced, and the production process has become very fast.
The next section will explain how it is made today.
How Are Eyeglasses Made Today Different From The Past?
Previously, in the 70s, lenses were made of glass only, and each one required grinding and polishing. It used to be a very labor-intensive process and took a lot of time to produce. The result was thick and heavy glasses; and lots of breakages.
Gradually, optometry technology evolved and started producing lens blanks for a wide variety of optical power. Lens stocks of a specific set of powers were available, making fabrication easier.
Between the mid-90s and early 2000s, lenses with higher-quality anti-reflective and anti-scratch coatings became available in plastic. The quality and varieties of coatings that were available both significantly improved. New manufacturing techniques and progressive lens technology advanced at virtually lightning speed.
Now it is simpler to produce lenses that fit the curvature of your cornea with injection molding. You can produce thousands of them with a machine that meets your demands.
The calculations and settings on the various devices involved are now mostly performed by computerized precise machines. Some production tasks require professional technicians. It is incredible how many timesaving tasks are being carried out by robots.
Thanks to advancements in technology, lenses can now more effectively fix a range of visual issues, including several variants of coatings. You can almost pick up your prescription glasses with all the coatings in just a few hours.